Sugar chain is a generic term of a molecule in which monosaccharides, such as glucose, galactose, mannose, fucose, xylose, N-acetylglucosamine, N-acetylgalactosamine, and sialic acid, and/or derivatives thereof are linked to each other via a glycoside bond to form a chain-like structure.
Sugar chains are very rich in diversity and they are substances involved in various functions that naturally-occurring organisms have. The sugar chain is often found as a complex carbohydrate, in which the sugar chain bonds to a protein, a lipid, or the like, in the body and it is one of the major constituents in the body. It has been revealed that sugar chains in the body are deeply involved in intercellular signal transduction, regulation of functions and interactions of proteins, and the like.
For example, as a biopolymer having a sugar chain, there may be mentioned cell wall proteoglycans in plant cells, which contribute to stabilization of cells; glycolipids, which influence differentiation, proliferation, adhesion, migration, and the like of cells; glycoproteins, which involve in intercellular interactions and cell recognition; and the like. There have been gradually clarified mechanisms in which these sugar chains contained in biopolymers control high-level and precise biological reactions while acting for, aiding, enhancing, adjusting, or inhibiting their functions with the biopolymers each other. Furthermore, if relationships of such sugar chains with differential proliferation of cells, cell adhesion, immunity, and cell canceration are clarified, it may be expected to make a new development by closely associating this glycoengineering with medical science, cell engineering, or organ engineering.
Patent Document 1 describes substances that specifically react with such sugar chains, and in addition, a method of separating sugar chains by using these substances and the like.    Patent Document 1: WO 2004/058687